Response of nodulated soybean cv. halesoy 71 to nitrogenous fertilization

Abstract

A nitrogenous fertilization trial with nodulated soybeans cv. Halesoy 71, was carried out on a Brunizem class II soil, according to its use capacity, in the locality of Fuentes, Santa Fe Province, during 1975-1976, season. Experiments were conducted in a completely randomized design with six replication per treatment. The effect of Ne additions was valuated on grain, stalk pod yield and on protein, lipid and ash content in grains. At Power bud apperance, the nitrogenous fertilizer (urea) was applied at the plant base. A lineal response to N, expressed as grain yield, was obtained with nodulated soybean; the highest dose used (200 kgs/N/ha) resulted in 15% grain increase. However 100 kgs/N/ha was the most effective dose (greatet conversion). Stalk and pod production was increased with N, being 13%a higher than that of the control at the maximum N level employed. The ratio stalk weight plus pods/grain weight was lower in fertilized, than in non fertilized plots, mainly because of greater grain production. No correlation was observed between "vaneo" --yield and "vaneo"- total N whereas grain yield was found to he highly correlated with the total number of pods per plant. Grain protein content was greater with increased amounts of fertilizer, the reverse occurring with lipid content. Ash amount was practically constant.. According to the results obtained, it is conc'uded that the soybeans crop can be increased by late nitrogenous fertilization.